California Environmental Protection Agency
Health Information on Asbestos
Asbestos is classified as a known human carcinogen by State, federal, and international agencies. It was identified
by the Air Resources Board (ARB) as a toxic air contaminant in 1986.
Asbestos minerals belong to either the serpentine mineral group or the amphibole mineral group. The most common
type of asbestos found in California is chrysotile, a serpentine mineral; other types include tremolite asbestos
and actinolite asbestos which are amphibole minerals. State and federal health officials consider all types of
asbestos to be hazardous. No safe asbestos exposure level has been established for residential areas.
The risk of disease depends upon the intensity and duration of exposure. Exposure to low levels of asbestos
for short periods of time poses minimal risk. Asbestos fibers can penetrate body tissues and remain in the lungs
and the tissue lining of the lungs and abdominal cavity. The fibers that remain in the body are thought to be responsible
for asbestos-related diseases. The illnesses caused by asbestos may not be observed for twenty or more years.
The most common serious diseases caused by asbestos are listed below:
Asbestosis: Asbestosis is a non-cancerous lung disease related to diffuse fibrous scarring of the lungs.
This disease has occurred in people heavily exposed to asbestos in the workplace and in household contacts of asbestos
workers. Asbestosis can cause progressive shortness of breath and coughing.
Lung cancer: Lung cancer is a relatively common form of cancer which has been linked to smoking and a variety
of occupational exposures. Cigarette smoking significantly increases the risk of lung cancer for those people exposed
Mesothelioma: Mesothelioma is a rare cancer of the thin membranes lining the lungs, chest, and abdominal
cavity. Almost all cases are linked to prior occupational asbestos exposure.
Most of the information on health effects comes from studies of people who were regularly exposed to high levels
of asbestos in the workplace. Workplace exposures are higher and much more likely to cause disease than non-workplace
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Almanac of Policy Issues. It is being preserved in the Policy
Archive for historic reasons.